Add strictSemVer option

README.md

@@ -85,6 +85,15 @@ Use `true` to ignore the recommended bump, and use the version provided by relea
 (Note that the changelog preview shows the recommended bump, as the desired version isn't known yet. The `infile` will
 have the correct version.)
 
+### `strictSemVer`
+
+Default value: `false`
+
+Use `true` to strictly follow semver, also in consecutive pre-releases. This means that from a pre-release, a
+recommended bump will result in a next pre-release for the next version. For example, from `1.0.0-alpha.0` a recommended
+bump of `minor` will result in a `preminor` bump to `1.1.0-alpha.0` (whereas the default behavior without this flag
+results in a `prerelease` bump to `1.0.0-alpha.1`).
+
 ### `context`
 
 Default value: `undefined`

index.js

@@ -47,7 +47,10 @@ class ConventionalChangelog extends Plugin {
         if (increment && semver.valid(increment)) {
           resolve(increment);
         } else if (isPreRelease) {
-          const type = releaseType && !semver.prerelease(latestVersion) ? `pre${releaseType}` : 'prerelease';
+          const type =
+            releaseType && (options.strictSemVer || !semver.prerelease(latestVersion))
+              ? `pre${releaseType}`
+              : 'prerelease';
           resolve(semver.inc(latestVersion, type, preReleaseId));
         } else if (releaseType) {
           resolve(semver.inc(latestVersion, releaseType, preReleaseId));

test.js

@@ -73,7 +73,7 @@ test('should use provided pre-release id', async t => {
   assert.strictEqual(version, '1.1.0-alpha.0');
 });
 
-test('should use provided pre-release id (prelease continuation)', async t => {
+test('should use provided pre-release id (pre-release continuation)', async t => {
   const options = { preRelease: 'alpha', [namespace]: { preset }, git };
   const plugin = factory(Plugin, { namespace, options });
   const stub = sinon.stub(plugin, 'getLatestVersion').returns('1.1.0-alpha.0');
@@ -103,6 +103,16 @@ test('should use recommended bump (after pre-rerelease)', async t => {
   stub.restore();
 });
 
+test('should follow true semver (pre-release continuation)', async t => {
+  const options = { preRelease: 'alpha', [namespace]: { preset, strictSemVer: true }, git };
+  const plugin = factory(Plugin, { namespace, options });
+  const stub = sinon.stub(plugin, 'getLatestVersion').returns('1.1.0-alpha.0');
+  await runTasks(plugin);
+  const { version } = plugin.config.getContext();
+  assert.strictEqual(version, '1.2.0-alpha.0');
+  stub.restore();
+});
+
 test('should use provided increment', async t => {
   const options = { increment: 'major', [namespace]: { preset }, git };
   const plugin = factory(Plugin, { namespace, options });